Printing a different print content on each page (called “variable data printing”) is a conventional practice, such as in the case of printing credit card bills or the like. In the variable data printing, rasterization (hereinafter, referred to as “RIP processing”) is performed on received data to generate raster data while images are being consecutively printed on objects such as printing paper in accordance with the raster data. Recent improvements in the printing speeds of printers have increased the demand for higher RIP processing speed.
The received data, which is page group data indicating many pages, is written in a page description language such as PostScript (registered trademark) or Portable Document Format (PDF). A page data piece indicating each page in the page group data in PDF format (part of the page group data) uses a plurality of page components. These page components are in such a nested relationship that one page component uses another page component and the other page component uses yet another page component. Japanese Patent Application Laid-Open No. 2002-182875 (Document 1) discloses a method of predicting rasterization time required for each job on the basis of the number of each type of drawing instructions included in data of the job, and figure size information.
Meanwhile, the nested relationship among page components may become complicated irrespective of the intentions of a data producer due to, for example, the way of using desktop publishing (DTP) software in generating page group data in PDF format. For instance, with page group data in which page components are nested to many hierarchical levels, the speed of RIP processing using Adobe PDF Print Engine (APPE) or the like may be reduced or the RIP processing may be terminated due to an error. With the method of Document 1, it may be difficult to accurately obtain a predicted value of a conversion processing time for converting page group data because factors such as transparency effects and the nested relationship among page components are not taken into consideration. In addition, obtaining only a predicted value of the conversion processing time is insufficient for an operator to ascertain the appropriateness of page group data (also referred to as “plane group data”).